Nuclear Data Sheets for A = 180

The 1965 version of the Nuclear Data Sheets was revised according to experimental data received prior to May 1974, including approximately 120 papers. Data are presented for nine nuclei (Lu, Hf, Ta, W, Re, Os, Ir, Pt, and Hg). Only alpha decay data are available for Hg and Pt. No excited states or gamma transitions are definitely assigned to Lu or Ir. A tentative decay scheme for Ir is presented. The decay schemes for Lu(5.7 m), Ta(greater than 1013 y and 8.1 h), and Re(2.43 m) are well established. The Os(22 m) decay scheme is still rather uncertain because of a lack of precision gamma-ray energies and intensities. The Hf level scheme includes 46 levels (23 J/sup π/ values), although only the groundstate rotational band has been established. Branching ratios for 179Hf(n,γ), /sup 180m/Hf(5.5 h) decay, and 180Lu(5.7 m) decay were compared, and several disagreements are noted. The W level scheme includes 32 levels (16 J/sup π/ values) with three proposed rotational bands, although several assignments are not well established. The Re level scheme includes 10 levels (3 J/sup π/ values), all due to Os decay. The Os level scheme includes 10 levels with J/sup π/values available only for the ground-state band. The most important deficiency in the data is that very few charged-particle reaction data are available except for (d,p) to Hf and (p,t) to W. (U.S.)